Various pedal operated means for propelling boats, kayaks & other watercraft have been proposed. For example, Kiker U.S. Pat. No. 3,032,001 describes a pedal operated boat propulsion apparatus; Price U.S. Pat. No. 4,318,700 relates to a paddle wheel operated watercraft having pedals to be engaged by the feet of a seated occupant; Daoud U.S. Pat. No. 4,474,502 shows a surfboard having handle bar, passenger seat and pedal, much like a bicycle, with propulsion being provided through a gear train to a rotary propeller; Fanelli U.S. Pat. No. 4,511,338 pertains to a detachable device for converting a said board into a water bicycle; Guiboche U.S. Pat. No. 5,183,422 discloses a pedal boat having a belt-driven paddle wheel; Shiracki U.S. Pat. No. 5,194,024 discloses a propeller driven surfboard; Gagnier U.S. Pat. No. 5,453,031 pertains to a propulsion device for a paddle boat; and Beres U.S. Pat. No. 5,460,551 relates to a pedal powered kayak wherein rotatable pedals are connected via a linkage to a propeller.
Stolzer U.S. Pat. No. 3,095,850 describes a foot operated paddle boat wherein the paddle is transversely sculled or twisted across the bow of the boat, the pitch of the paddle being reversed at each reversal of path direction to provide propulsion force in both directions of paddle travel. Stolzer U.S. Pat. No. 4,960,396 relates to a modification in which a rigid planar paddle blade is used. The devices are limited in the propulsive force which they provide.
The Boston Globe, May 13, 1997, reports on a mechanically powered propulsion system for ships undergoing development at Massachusetts Institute Of Technology which employs as the ultimate propulsion means a pair of flappers said to mimic the flapper motion of a penguin described as being like holding ones arms straight down with the hands open, then bringing the arms together in a clapping motion while rotating one's hands. The system includes four different motors to produce the flapping and twisting functions, all guided by a computer and complex circuiting.